The surface effect on the mechanical behavior of MG nanowires: A molecular dynamic simulation

The surface is crucial for the properties of a nanoscale metallic glass structure. How the atoms organize on the surface and affect the properties remains unclear. Here, we investigate the surface effect on the mechanical behavior of metallic glass nanowires via molecular dynamic simulation. The results show that the surface-induced Laplace pressure produces considerable pressure inside the nanowire, which causes a denser internal atomic packing and contributes to high ultimate strength. Besides the effect on the internal, the atoms on the surface are arranged uniquely. A layering structure is found on the surface of metallic glass nanowires, suggesting a certain level of order on the surface. The mechanical response is strongly dependent on the order of the surface and the mechanisms are analyzed from the perspective of the atomic deformation pattern. The influence of size on the surface effect is also discussed in detail.